Merge branch 'docs/ssot_scim_setup' into 'master'

Edit "SCIM Setup" for SSOT

See merge request gitlab-org/gitlab-ce!29313

doc/user/group/saml_sso/scim_setup.md

+---
+type: howto, reference
+---
+
 # SCIM provisioning using SAML SSO for Groups **[SILVER ONLY]**
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9388) in [GitLab.com Silver](https://about.gitlab.com/pricing/) 11.10.
 
+System for Cross-domain Identity Management (SCIM), is an open standard that enables the
+automation of user provisioning. When SCIM is provisioned for a GitLab group, membership of
+that group is synchronized between GitLab and the identity provider.
+
 GitLab's [SCIM API](../../../api/scim.md) implements part of [the RFC7644 protocol](https://tools.ietf.org/html/rfc7644).
 
 Currently, the following actions are available:
@@ -100,3 +108,15 @@ the `Provisioning Status` to `ON`.
 
 Once enabled, the synchronization details and any errors will appear on the
 bottom of the **Provisioning** screen, together with a link to the audit logs.
+
+<!-- ## Troubleshooting
+
+Include any troubleshooting steps that you can foresee. If you know beforehand what issues
+one might have when setting this up, or when something is changed, or on upgrading, it's
+important to describe those, too. Think of things that may go wrong and include them here.
+This is important to minimize requests for support, and to avoid doc comments with
+questions that you know someone might ask.
+
+Each scenario can be a third-level heading, e.g. `### Getting error message X`.
+If you have none to add when creating a doc, leave this section in place
+but commented out to help encourage others to add to it in the future. -->